1、 Preface

1) The primary domain server name is DC1, and the IP address is

2) The computer name of the secondary domain server (that is, the additional domain controller server to be added now) is DC2 and the IP address is

2、 Add additional domain controller

2.1. Open DC2 server manager and click “add roles and functions”.

2.2. Click “next”.

2.3. By default, click “next”.

2.4. By default, click “next”.

2.5 check “active directory domain services” and “DNS server” and click “next”.

2.6. By default, click “next”.

2.7. Click “next”.

2.8. Click “next”.

2.9 check “automatically restart the target server if necessary” and click “Install”.

2.10 after installation, click “close”.

2.11. Click the yellow exclamation mark in the lower left corner of “manage” in the upper right corner of the target manager, and then click “promote this server to a domain controller”.

2.12. Default option, input the password of restore mode and click “next”.

2.13. Click “next”.

2.14, copy from the selected primary domain “DC1 linkto.com Click next.

2.15. Change the path of each folder and click “next”.

2.16. Click “next”.

2.17. Click “Install”.

2.18. After installation, the server will restart automatically. This completes the installation of the additional domain controller.

3、 Additional domain controller check

3.1. Open DC2 server manager, click Tools, and select active directory users and computers.

3.2 in the domain controllers directory, you can see that there are more DC2 domain controllers.

3.3 in the “users” directory of the domain controller, you can see that the domain users have also been copied.

3.4. Open DC2 server manager, click “tools”, and select “DNS”.

3.5. You can see that the familiar directory has been copied.

4、 Additional domain controller authentication

4.1. The DNS of DC2 is working normally. Therefore, the IP addresses of computers (servers and clients) in all domains are set there. For standby DNS servers, please set the IP address of DC2, i.e. “”.

4.2. If you continue to add additional domain controllers, that is, there are multiple DNS addresses, you can do this as follows:

1) In the IP address settings, click Advanced.

2) Select the “DNS” option page and click “add”.

3) Enter the IP address of DNS server and click Add.

4.3 use Win + R to call up the operation window, input “MMC”, and click “OK” to call up the console program.

4.4. Click “file” and select “add / delete management unit”.

4.5. Add two “active directory users and computers” and click “OK”.

4.6. Right click the first active directory user and computer and select change domain controller.

4.7. Select the primary domain controller “DC1 linkto.com “。

Active directory users and computers [DC1 linkto.com ]Add a user on sales03 Wang Wu.

4.9. You can see that the new user Wang Wu on DC1 will be copied to DC2 soon.

4.10. Disconnect the network of DC1 on the virtual machine. If Wang Wu can log in to the domain normally at this time, it is proved that DC2 has taken over the authentication of DC1.

4.11. Log in on the client host sales01 with Wang Wu’s account (the backup DNS has been set to the IP address of DC2), you can see that you can log in normally.

4.12. In this way, with the additional domain controller, if the primary domain DC1 fails to work due to downtime, the secondary domain DC2 will take over the work to achieve fault tolerance.